The lymph node ratio as a prognostic factor for gastric cancer

Area of Science:

• Oncology
• Surgical Pathology

Background:

• Accurate gastric cancer staging is crucial for prognosis.
• The Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) TNM system is standard but requires sufficient lymph node retrieval (≥15) for accurate N staging.
• Inadequate lymph node counts can lead to understaging.

Purpose of the Study:

• To compare the prognostic accuracy of the lymph node ratio (LNR) staging with the UICC/AJCC TNM classification for gastric cancer.
• To evaluate the reliability of LNR as an alternative N staging method.

Main Methods:

• Retrospective analysis of gastric cancer patients diagnosed between 2000-2009 who underwent surgery.
• Patients were staged using both UICC/AJCC TNM (5th/6th or 7th edition) and LNR.
• Survival analyses included crude survival, univariate, and multivariate analyses.

Main Results:

• Five-year overall survival rates varied from 58% (N0) to 18% (≥15 metastatic nodes) using TNM staging.
• Five-year overall survival rates ranged from 58% (LNR0) to 10% (LNR3) using LNR staging.
• Both TNM and LNR were significant prognostic factors for survival.
• LNR demonstrated a lower correlation with the number of lymph nodes examined.

Conclusions:

• Lymph node ratio (LNR) is a valuable prognostic tool for gastric cancer overall survival.
• LNR is an independent prognostic factor with more consistent hazard ratios and survival rates than UICC/AJCC systems.
• LNR is less susceptible to stage migration due to its lower correlation with the number of examined lymph nodes.